The invention relates to a system for the compatible transmission and/or recording of progressively scanned picture signals in line interlaced scanning format.
Published European patent application W091/04637 describes a letter-box television system in which 432 active progressively scanned lines are compatibly transmitted, with the aid of a so-called "helper" signal, in line interlaced scanning format. In this system, in addition to losses due to vertical transcoding, ideal horizontal edge information for progressive scan image reproduction cannot be transmitted, resulting in reduced picture quality.